New environmental laws and regulations mandate that coating products, such as architectural coating compositions, must be low in volatile organic compounds ("VOCs"). These environmental measures have caused problems of compliance for manufacturers and users of coating compositions containing VOCs. New "VOC-compliant" coating products are said to leave a lot to be desired, especially when compared to the favored, old, oil-based coating products (which contain as much as 60% solvent) Giegerich, A., "Brush With the Law," Building Products, Fall 1991, p. 91.
Paint formulators and users continue to come up against new and more complex government air quality regulations affecting solvent use in paints and coatings. The mandates of the U.S. Government under the Clean Air Act of 1990 to ban solvents considered to be hazardous air pollutants ("HAPs") will soon go into effect, forcing paint formulators to reformulate. This legislation also encourages cuts in solvent use in congested urban areas where the VOCs--released as the solvents evaporate--combine with nitrogen oxides to produce smog. Under the Clean Air Act, a series of HAPs must be reduced. And because of the ozone-depleting potential of chlorinated solvents, paint formulators must remove these solvents from their coatings as well. So, some users might switch to alternatives such as high solids-low solvent formulas, heat-fusible powder coatings, radiation-cured coatings, waterborne coatings, water-based formulations containing fewer solvents, and use of oxygenated or hydrocarbon solvents as substitutes for chlorinated solvents Reisch, M. S., "Paints & Coatings," Chemical & Engineering News, October 18, 1993, p. 34.
Patent literature also discloses the need to limit the amount of VOCs in coating compositions in order to meet statutory regulations or guidelines. For example, U.S. Pat. No. 4,615,739 (Clark et al.) describes an "oil-in-water-in-oil" coating composition having a low VOC content and which can be formulated to meet or substantially comply with environmental standards.
U.S. Pat. No. 4,814,016 (Adkins et al.) describes an invention directed toward VOC limits for penetrating coatings established by the State of California under the Clean Air Act. That invention is described as a waterborne penetrating composition for protecting wood surfaces comprising certain maleinized linseed oils, water-reducible alkyd resin, and a water-propylene glycol tertiary butyl ether coupling solvent. One to three weight percent of an aliphatic or isoparaffinic hydrocarbon, for example, the aliphatic hydrocarbon available under the trademark ISOPAR, can also be included to control evaporation of the solvent component.
U.S. Pat. No. 3,422,044 (Erikson et al.) describes an aqueous coating composition comprising a heat-bodied maleinized glyceride oil, and the composition can include a synthetic polymeric latex, such as that of a copolymer of styrene and butadiene.
U.S. Pat. No. 3,272,642 (Nelson) describes baking an applied coating composition of certain homopolymers or copolymers of butadiene-1,3 modified with maleic anhydride and mixed with alkyl esters or metal alcoholates to aid the curing of the butadiene polymer, which can be made by polymerizing butadiene-1,3 in mineral spirits ("Varsal") and then reacting it with maleic anhydride.
U.S. Pat. No. 3,959,198 (Breacker et al.) describes heat-curable resins which can be diluted with water and are suitable for electrophoretic coating, the resins being based on certain reaction products of maleic anhydride with mixtures of certain polybutadienes, unsaturated hydrocarbon resins, and unsaturated fatty acid glyceride esters; the mixture can also include an adduct of certain unsaturated dicarboxylic acids.
Other patents describing various coating compositions or substances containing or made from butadiene polymers or other substances modified with maleic anhydride are U.S. Pat. No. 3,284,380 (Davis), U.S. Pat. No. 3,925,279 (Horii et al.), U.S. Pat. No. 4,272,417 (Barke et al.) U.S. Pat. No. 5,266,646 (Eishenhard et al.) U.S. Pat. No. 5,242,716 (Iwase et al.), U.S. Pat. No. 5,256,226 (Marzola et al.) U.S. Pat. No. 5,264,479 (Heinz et al.), and U.S. Pat. No. 5,281,663 (Gelles).